1221838464 has 384 divisors, whose sum is σ = 4278320640. Its totient is φ = 299980800.

The previous prime is 1221838463. The next prime is 1221838483. The reversal of 1221838464 is 4648381221.

It is a tau number, because it is divible by the number of its divisors (384).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221838463) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28414827 + ... + 28414869.

It is an arithmetic number, because the mean of its divisors is an integer number (11141460).

Almost surely, 2^1221838464 is an apocalyptic number.

1221838464 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221838464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2139160320).

1221838464 is an abundant number, since it is smaller than the sum of its proper divisors (3056482176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221838464 is a wasteful number, since it uses less digits than its factorization.

1221838464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140 (or 97 counting only the distinct ones).

The product of its digits is 73728, while the sum is 39.

The square root of 1221838464 is about 34954.8060214901. The cubic root of 1221838464 is about 1069.0661966782.

The spelling of 1221838464 in words is "one billion, two hundred twenty-one million, eight hundred thirty-eight thousand, four hundred sixty-four".